never gonna grow up

Firing up the Trailmaster

If you’ve operated a power mower you probably already know the routine. Turn on the electrical system of the Trailmaster XRS Mid.

The gas will be off.

The run and choke controls are located on the back of the motor, on the right side when you stand behind the kart looking at the motor.

Turn the gas on using the bottom lever. The top lever is the choke. The choke’s purpose is the let you give the engine a richer mixture for starting and then lean it out once the engine is started and warmed up. You’ll probably want to use full choke to start a cold engine. If the engine has been running it will probably need only mid choke or no choke at all.

For the bottom lever, left is off (no gas) and right is run.

For the top level, left is full choke, there’s a detente in the middle for half choke useful for when the engine isn’t yet totally warmed up, or for starting a warm engine. All the way to the right no choke, or the leanest mixture.

Let the engine idle a bit. Don’t worry, the kart won’t move as the clutch won’t engage. Nevertheless, you should have the kart in a position where it can not get away from you. After the engine warms up, push the choke lever to mid or all the way off (to the right).

Now you’re ready to rock’n’roll. Have your guy put on his helmet and some glasses or goggles to protect his eyes from dirt getting kicked up from the wheels and let ‘er rip.

Oh, one more thing, the engine idle setting. This is adjusted with a plastic screw and it wasn’t real obvious from the manual where this screw was located. It’s below the air filter/carb assembly where my finger is pointing.

Now you might say you don’t see a screw there. You are correct. I broke it off right away not realizing it was plastic. I don’t think I forced it, but I was scrambling to get things going with my kids standing around expectantly, so who knows, I probably did mess up.

I was able to dig out the broken off screw using small needle nose pliers. I found a screw that seemed to fit (#5 metric) but I couldn’t see what it should engage with. So at this time, I’m doing without and it’s idling fine. It’ll stall every once in a while, but not too often.

If anyone knows what this screw should engage with, let me know. There’s a little lever behind there but the tension screw pulls it away from the idle adjust instead of into the idle adjust screw.

Specific steps to start

Here is the list of exact steps to start the kart:

Turn on the electric system (switch shown above).

Push the bottom gas lever all the way forward to turn on the flow of gas to the engine.

Pull the choke lever all the way back to start a cold kart

Pull the starter cord. It might take a couple pulls. The engine should fire up and start chugging at a relatively low idle speed. If it takes more than a couple pulls, check the settings of the switch and levers.

Let the engine warm up for 30 seconds and then move the choke lever to the middle detent. The idle should increase a bit and you’re ready to drive.

Later, after 5-10 minutes of driving you can move the choke lever all the way forward to lean out the mixture completely.

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2 thoughts on “Firing up the Trailmaster”

I just purchased the XRS mid. The kids had a great 3 days on it and then we started having problems…maybe you can advise? The engine starts and runs just fine and then they push on the gas peddle and nothing happens. Obviously, I know nothing about engines/go-karts and have no idea why this is or what I need to do. Any reply is appreciated!

Look at the other end of the throttle linkage cable back by the engine. Watch what moves when you hit the gas. Does it move the lever on the carb? A bolt came lose on mine causing same problem. In fact several bolt have loosen with vibrations of the kart. Both bolts on the gas tank came off leaving it hanging by gas tube.